Composite insulated wheel



y 1950 w. R. SMITH 2,507,483

COMPOSITE INSULATED WHEEL Filed Nov. 4, 1944 ZIII'I/III/II/I/Iij IN VEN TOR.

ATTOF/Vf) imam 515mm;

Patented May 9, 1950 UNITED STATES PATENT OFFICE COMPOSITE INSUL-ATEDWHEEL 7 William R. Smith, Philadlphimlia assignorto The A. 0. Gilbert Company, New Haven, 001111.,

a corporation'ofMaryland V v Applicationx'November 4, 1944, Serial Nth-5613963 11 Claims. (01. 10'5 122-) .1 V z'lihis invention relates to sectional wheels .in which a felly or. rim section is electrically'insuylated'from a central or. hub section of the wheel particularly :concerns sectional wheel structures and-methods of manufacturing the same better-suited to mass production of small wheels of very simple construction such asthe traction .or driving. wheels of a toy locomotive or some .othercar in a toy electric train. i

In so-ca-lled two-railelectrified toy railroads v.it is necessary for one of the two track rails to .serve .asa current feeder :while theother track rail serves-as .a return conductor for the current that energizes the driving motorof the toy locomotive. Inorder to complete a power circuit through the motor :from one track rail to the other, certain traction wheels ofthe toy cars or locomotive ,may be conductive as usual and serve -.as a current:collectortov maintain the locomotive motor. in circuit with the track. Wheels on transversely opposite sides of thesame .toy car however need to belinsulativeras between the car .body and the track 'railon which they roll in .order to prevent vshort circuiting th electric motor. Asit isundesirable to make the whole of such wheels out of .-insulating..material 'itlbe- .comes necessar to insulate therim portion of the. wheel from the hubof the wheel.

,Itis .one object of 'the present improvements to provide a sectional wheel inwhich the hub .sec-

tion is insulated from the rim section .so that the .glatt'er section whichrolls. on the .rail may, if degsired, be made-ofmetal for maximum protection .;against wear and-breakage or becoming out of round. .Another object is toiintroduce the necessary electrical insulation into the wheel structure apart from zanynpr ocess ofmoldingor metal casting that is employed .in production of the wheel .sections, therebyto avoid costly complications of molding equipment and to avoid processes which slowdown-the .speedof-output inmass production. A related object .is to introduce .a preformed Linsulativev body into the wheellstructure by me- ;phanicalassemblage of suchlbody with separate .ehub-and-rim sections ofithe wheel.

A iurther object is to-employ amethod of mechanical assemblage which will hold-the wheel sections-fixedly and permanently together .in a

.nnified structure without requiring any .extraneous fastening means and yet will -;permit ready v.clisasseml'ilage oi the wheel sections when-desired and itheir replacement interchangeable Par ;a. valuable-creature in mass .Ptoduction of :secti'onal units vmere it .is often desired to stock 1'2 interchangeable parts of similar -or difiering characteristics capable of selective assemblage with one another. r

Still further objects are in a toy locomotive drive wheel to dispose the insulativebody in-zthe wheel structure in away to prevent electrical contact between the electrically alive rim of nth-.

trouble and expense of surface coating processes if the insulative. body .is made .from,.any of vthe commonly available molded plastics.

These and other objects of. the invention. will become clearjingreater detail from the following description of, a preferred embodiment .andposlsible modifications thereof, in which. description reference is "had to the accompanying drawings wherein: a,

Fig. 1 is a jbroken away isometric. viewfora itoy locomotive wheel considerably enlargedembodying the presentimprovements and also .shows a section of thejtoy trackrail on whichjit rolls .as wellas' a fragment'of ap'itm'an link for transmitting rotary motion to or from the wheel. Fig. 2 is a lateraloutsideview ofthe'bare'whee'l of Fig. 1 shown in a typical ,actual size. 7

Fig. .3 is an edge view of the wheel looking'from the right at Fig. 2.

, Fig. 4 is a view of the inside face of the wheel. ,Fig. 5 is .an exploded isometric view of "three sections of the wheel drawn on a scale inter mediate that of Figs'l and 2. y

Fig.6 is a fragmentary view drawn .on thesame scale asFig. 1 taken in section on a diametral plane passing through the center. of the wheel Thestructure of my improved wheel shown in Figs. 1 to .601? thadrawingsis of sectional orcomposite. character. made up of three major .parts which I. shal l .refer to as the hub section J 0,. the iellyzor mm section 1L! and a ring-like member [2 55 .or insulativeamaterial.

The rim section H may consist of metal, die cast or otherwise formed. For use at the perimeter of a chassis wheel for toy locomotives or other toy railway cars, rim section II may be equipped with a guard flange l3 at its inner edge adapted to exert lateral thrust against t rail ll of an electrified toy railway track.

The hub section I contains a central axial bore H to receive the wheel axle whose other end will carry a wheel somewhat similar to that herein shown except that it need not have the insulative feature with which these improvements are concerned. After the fashion of the traction wheels of full size rolling stock, hub section 80 may be cast to configure its outer face l8 as shown in Figs. 1 and 2. This imparts the appearance of spokes. Outstanding from hub face I 8 there is commonly cast a bearing boss 19 containing a threaded hole 24 to accommodate the screw 20 whose crank pin forming shoulder 2| afiords free pivotal bearing for one end of a pitman link 22 whose opposite end may connect to associated moving parts of the impelling gear of the toy locomotive such as a piston rod or some other drive wheel on the same locomotive for transmitting motion to or from the insulative wheel herein concerned. 23 denotes a thrust washer reducing any friction of rubbing that might occur between pitman link 22 and the head of screw 20.

In the present improvements there is interposed between rim section I i and the hub section lo the before mentioned ring-like insulative member [2 assembled in a manner that holds these rim and hub sections fast together in electrically insulated relation without resorting to any extraneous fastening means and without bonding any one section or member to any other section or member by means of a molding or casting operation or in any other way that would preclude their being taken apart at will. Permanent and dependable fixity of the assemblage herein proposed is attained purely by mechanical pressure applied in forcing together the three parts shown in Fig. 5. This might be done in a simple arbor press.

It will be observed that ring member l2 has a. barrel portion 26 whose wall thickness tapers, whose outer surface 21 is cylindrical and whose inner surface 28 is conical. This ring member also presents a flange-like shoulder 29 projecting radially outward beyond cylindrical surface 21 and in its assembled position flanking the outer side face ii of the rim section II. The thinnest section of the tapering wall of barrel 26 is preferably at or near the flange shoulder 28.

Since cylindrical surface 21! is perpendicular to the plane of flange 29 while conical surface 28 slants in relation to such plane there will be a tight wedging effect when, after the ring member I2 is sleeved by the closely fitting cylindrical surface 21, hub section I0 is pressed telescopically into place as shown in Fig. 6. This forcing of the hub section axially into its assembled position will drag axially on the ring member i2 and cause the hub section to rub in sliding contact with the ring member after the axial movement of the latter is arrested by its flange 29. Thereafter, relative axial movement between hub section l0 and the rim sleeved ring member [2 will tightly wedge the hub section into the ring member in a telescopic manner and in a direction to squeeze and slightly compress the material of the ring member radially between the wheel sections. For this effect the ring is preferably hard throughout and need be only minutely tensile if at all in Figs. 6 and 7. In these forms of the invention no stretching of the ring will be occasioned if its cylindrical surface is an exact fit for the matching cylindrical surface of the wheel section, while in Fig. 8 where all surfaces are conical, the ring 42 requires no tensile property at all.

The degree of compression of ring member I2 is also preferably minute and may for practical purposes amount to a squeeze of two to four thousandths of an inch whereby permanent concentric fixity of the assemblage is assured while leaving the parts free to be disassembled by reverse axial forced pressure. True concentricity of the rim section in relation to the bore H of the hub section 10 results.

Without intent of prescribing any limits as to sizes or relative fits of parts capable of successful assemblage according to the principles of this invention, the following examples of relative dimensions are considered satisfactory in the art of toy train construction. The rim section 1 0 may have a cylindrical inside diameter of 1.032"

: as compared with a diameter of 1.030" for the cylindrical surface 21 of the ring member l2. The hub section 0 may have a conical periphery tapering from .045" diameter to .955 diameter along an axial length of about as compared with dimensions of conical surface 28 of ring memebr l2 tapering in about the same axial length from .940" to .950". It will be seen that the tapers of the hub section and of the insulative ring member may be substantially alike producing, when the hub section is forced home, the before mentioned squeeze or compression of say, .0025" in the radial thickness of barrel 26 of ring member [2. These dimensions will work satisfactorily if the member I2 is independently molded of an ordinary thermoplastic such as cellulose acetate materials now on the market. Well understood properties of such materials are their very slight degree of compressibility. They also are non elastic to any appreciable degree. Used as herein proposed, the consequent rigidity and resistance to distortion of a ring of such material dependably establishes and preserves without outside assistance true concentricity of the rim section H relative to the bore I! of hub section I0.

In Fig. '7 there is illustrated a reversal of some of the features of ring member l2 in that the barrel 26' tapers in like fashion to barrel 2%; but differs in having an inner cylindrical surface 34 while the outer surface 35 is conical. In this case the flange 36 projects radially inward instead of radially outward with respect to barrel 26. Thus flange 36 overlies face l8 of hub section I0 instead of overlying the face of rim section I I. In the modified construction of Fig. 7 the perimeter of the hub section I0 will be conical and may conform to the ring member according to relative fits as above explained.

In either of the herein illustrated forms of this improved composite wheel, the pitman link 22 is effectively prevented at all times from making electrical contact with either the rim section H or II by the annular continuity of flange 29 or 36 which intervenes and acts as an insulative spacer between the pitman link and the outside face of the wheel.

An appearance of attractively decorative circular banding of the rim of the wheel will result without any separate process of surface c'ol-' oring if the body of ring member 12 or I2 is composed ofrwhiteonbrightlynploredgplastia ma:

terialrwhosanaturgl surface .colon. contrasts inglycwith the;.-relati-velm dullzsurfacegann la-n Ofetheiside .face.. of.-.onel..oroboth ofzythe wheeler broad sense; COIItGmDISJtC;fithfictQlQSQOPiQzfiSS blage ofianyindependently .preformedicond t and 1iinsulative.- par-tar. insulative: flange? 29; might;:be=disposedrto. overlie ithe ir-xsid fao, stead nf :the voutside face-sofa. thee-wheel.

barrel pgrtion of ring membgaAZ is conical n;

sush -a gular accordance with the inner coni l on-fo mi egi s o t per pi .-.-.With; the fi barrelsurface M of ring 'member M. low g hreiexamples of dimensions of p been foundto telescope suogessfully into ne noth r;=: ith-.; r fi im-t ses as? shownin 8 where the materialepf which ing member 42;. is composed is a ldable thermo plastic material preferably of th ellulose;acetate tra s-1:. .orvn commonly reech.tr ametes Tenite 1, Lumarith l lixonite etc. The conical bore in rim section--44*may' taper from 1.032 inside diameter to 1.022 inside diameter in an Qal, width of 188.57.. 'i'hecon cahhar-r k ng ber'e 42=cr msuianng..maieria ay er theesame axial widthiromm e. eter to 1.025"

i ,.5... outside diameter. The conical bore in ring member 42 may taper from .950" diameter to .940" diameter along an axial width of .218. The conical perimeter of hub section 45 may taper from .955" to .ME') along the same axial width.

Axially tapering spacer blocks preformed of insulative material and circumferentially spaced may be substituted for the annularly continuous ring member l2 or IE and correspondingly wedged between the hub and rim sections of the Wheel, such blocks having end shoulders abutting the side face of the wheel to serve the purpose of flange 29 or 36. A press fit of the insulative ring member may serve some of the purposes of these improvements if the barrel 26 has no taper at all. These and all other variations of the basic novelty of construction disclosed herein are contemplated and intended to be covered by the various following claims.

Iclaim:

l. A sectional wheel of small size for toys embodying in rigid combination, a hub section and a metallic rim section, at least one of said sections having a conical surface facing radially toward the other of said sections, together with a minutely tensile minutely compressible ring comprising a hard barrel of electrical insulating material having a hard conical barrel surface conformingly abutting against said section surface, said barrel being wedged compressively between said sections with sufficient tightness to produce unaided and with concentric flxity a rigid assembly of said ring and sections maintained be dispensedwithgentirelys the gringememhe -gthella 4ov sections;

vathae rietiona siclin barrel ispurnosel .r lc e dition. A.- ec ionalfle in -defined l l im 1 a. which hasaid 1g are i tin hesid o e sthe saicl -11; secti n he i f e e-el sit. for t. dyingi n. a hub of ;electriQalundu at n m tsri internal conic l; b rrel-1... atria.

15. abutting aeainstzsa d.eoeiee a xt a, 1

lindrical barrel ylindrical in ernals said-..;ba,rre1.eb6il .i BQE ai p e et tion-.rfurther axially f the-.lattere is ti htly gee-.19.-

r:rrhametnodeoema ipsaerle g i ia g argl tively insulated rim and hub sections each hav ing a conical circumferential face, which involves placing in conical engagement with one of said wheel sections for reinforcement thereby a firm ring-like body of electrically insulative material having a barrel whose internal and external surfaces are both conical, and then rubbing said conical face of the other of said Wheel sections in slid- 59 ing contact with said barrel in the proper axial direction to wedge said barrel between said wheel sections.

6. A composite traction wheel for toy electric railway rolling stock, comprising three sections adapted to be telescopically thrust together in assembly including a hub section, a traction rim section, and an insulative ring mem ber sleeved between said sections having an annular flange overlying the outer face of at least one of said my wheel sections and having an internally tapering barrel portion increasing in thickness of barrel wall as it extends away from said annular flange.

'7. A composite traction wheel as defined in claim 6, in which the said annular flange of the ,5 said insulative ring member is composed of solid minutely tensile minutely compressible thermoplastic material colored throughout to appear in sharp contrast with the surface of said rim section adjacent said flange thereby to produce said contrast without coating the surface of said ring member.

8. In impelling gear for a toy electric locomotive, the combination of a traction wheel having a radially inner hub section and a radially outer rim section having a side face of electrically conductive material, a pitman link of conductive material, a crank pin carried in a circular orbit by said hub section and pivotally connecting said pitman link to the latter in a manner to swing closely adjacent the side face of said rim section for transmitting motion between said wheel and associated moving parts of the impelling gear, and an annularly continuous spacer of insulative material on said wheel encircling said crank pin orbit and projecting toward said pitman link sufficiently to guard against contact of the latter with said conductive face of the rim section.

9. In impelling gear for a toy locomotive, the combination defined in claim 8 in which the said insulative material of the said annularly continuous spacer extends between and insulatesthe said wheel sections from each other.

10. A sectional wheel of small size for toys embodying in rigid combination, a hub section having a cylindrical external surface and an encompassing rim section having a conical internal sur face, together with a minutely tensile minutely compressible ring comprising a hard barrel of electrical insulating material having a hard internal cylindrical barrel surface conformingly fitting said cylindrical external surface of said hub section and having a hard external conical barrel surface conformingly abutting against said conical internal surface of said rim section, said barrel being wedged compressively between said sections with sufiicient tightness to produce unaided and with concentric fixity a rigid assembly of said ring and said sections maintained by the frictional cling therebetween until said barrel is purposely released from its wedged condition.

11. A sectional wheel of small size for toys embodying in rigid combination, a hub section having a conical external surface and an encompassing rim section having a conical internal surface, together with a minutely tensile minutely compressible ring comprising a hard barrel of electrical insulating material having a hard internal conical barrel surface conformingly abutting against said conical external surface of said hub section and having a hard external conical barrel surface conformingly abutting against said conical internal surface of said rim section, said barrel being wedged compressively between said sections with sufficient tightness to produce un-' aided and with concentric fixity a rigid assembly of said ring and said sections maintained by the frictional cling therebetween until said barrel is purposely released from its wedged condition.

WILLIAM B. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATE-S PATENTS Number Name Date Re. 6,116 Ray Nov. 3, 1874 189,388 Sammis .Apr. 10, 1877 626,591 Cannon June 6, 1899 698,110 Foy Apr. 22, 1902 905,031 Wanta Nov. 24, 1908 1,067,628 Willie July 15, 1913 1,500,317 Hayes July 8, 1924 1,693,576 Hale Nov. 27, 1928 1,714,290 Alden May 21, 1929 1,745,153 Dalton Jan. 28, 1930 2,016,828 Brownyer Oct. 8, 1935 2,113,379 Maas Apr. 5, 1938 2,171,923 Fischer Sept. 5, 1939 2,267,629 Van Over Dec. 23, 1941 FOREIGN PATENTS Number Country Date 193,533 Germany 1906 600,616 Germany July 27, 1934 804,191 France July 27, 1936 Patent No. 2,507 ,483

Certificate of Correction May 9, 1950 WILLIAM R. SMITH It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 28, for f.045 diameter read .945 diameter; column 6, line 56, after the Word including insert a comma;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 5th day of September, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

